Transcript Chapter 11 Lesson 4

Chapter 6
Lesson 3 (Part I)
“Names and Formulas for Ionic
Compounds”
I. Oxidation Charges
A. Def – a positive or negative number
assigned to an atom or compound.
1. Use the Periodic Table
2. Ex: Lithium
a. Li loses 1 electron and becomes 1+
3. Ex: Fluorine
a. F gains 1 electron and becomes 1-
II. Binary Compounds
A. Def – composed of 2 elements
1. Ex: Sodium Chloride (NaCl)
2. Groups 1-8 have set oxidation numbers. (1, 2,
3, -3, -2, -1, 0)
B. Multiple Oxidation Numbers
1. Transition Metals
a. Use Roman numerals to represent charge
-Ex: Cu (II) = Cu2+
-Ex: Cu (III) = Cu3+
*Metals always have a positive charge / lose electrons
III. Writing Formulas
A. 4 step system
1. Write the Symbol with positive oxidation #
2. Write the Symbol with negative oxidation #
3. Done if superscripts equal zero. If unequal #4
4. Criss Cross Method
B. Ex: Chlorine and Sodium combine
Na1+
+
Cl1-
=‘s 0
Oxidation numbers equal zero
NaCl
C. Sodium combines with oxygen
1. Na1+ + O2rule #4
Na 1+
O 2-
Criss Cross
Drop the superscript
charges
Na2O
*oxidation numbers equal zero
Examples
1.
2.
3.
4.
5.
6.
7.
8.
Sodium Fluoride
Calcium Chloride
Aluminum Oxide
Iron (II) Chloride
Iron (IV) Bromide
Copper (II) Nitride
Magnesium Oxide
Mercury (I) Nitride
IV. Naming Binary
Compounds
A. 4 step system
1. Write the name of the 1st element
2. Write the “root” name of the second
element.
3. Add “ide”
4. Check for Transition Metals
B. Ex: CaCl2
Chlor
ide
1. Calcium
2. Examples
K3N
Al2S3
Mo2O
FeCl3
ZnF2
V. Polyatomic Ions
A. Def – having many atoms
1. Works as a covalent group
2. Have a single charge (usually negative)
3. List of Polyatomic Ions – pg. 173
B. Naming
1. Write name of positive ion
2. Write name of negative ion
3. Check for Transition Metal
4. Ex: NaNO3
Nitrate
Sodium +
C. Writing the formula
1. Write symbol of positive ion
2. Write symbol of negative ion
3. Check oxidation #’s to see if they equal zero
4. Criss Cross Method
-Use parenthesis to “set apart” a
polyatomic ion when more than one is
needed.
5. Ex: Write the formula for calcium nitrate.
12+
(
)
NO3
Ca(NO3)2
Ca
Reminders with Transition
Metals



For naming compounds with transition
metals always include the Roman
Numeral.
To determine the oxidation number of a
transition metal in a formula add up all
charges of the opposite ion.
Chemical formula do not need Roman
Numerals.
Chapter 6
Lesson 3 (Part II)
“Names and Formulas for
Molecular (Covalent) Compounds”
•
•
•
•
Common prefixes
Only use with non-metals
Pg. 175
**Do not use ionic charges!!!**
Prefix
Mono-
Number
1
Di-
2
TriTetra-
3
4
PentaHexaHepta-
5
6
7
OctaNonaDeca-
8
9
10
VI. Naming Molecular
Compunds
A. Rules
1. Most metallic element listed 1st
2. Prefix + element name
3. Prefix + element name + add “ide”
B. Ex:
N2O4
Di Nitrogen
Tetra Oxygen
Oxide
B. Name the following molecular compounds.
1. CO
2. H2O
3. NO
4. N2O
5. C4H8
6. Br2F8
7. P2O5
C. Writing Formulas for Molecular
Compounds
1. Use the prefixes for each element
and convert them to subscripts
2. Ex: Tetraiodine nonaoxide
= I4O9
3. Ex: Dicarbon pentafluoride
= C2F5
D. Write the formulas for the following
molecular compounds
1. Carbon Dioxide
2. Sulfur Hexafluoride
3. Phosphorus Tribromide
4. Diphosphorus pentaoxide
5. Carbon Heptaoxide
6. Dicarbon decafluoride